Method and apparatus for volume and consistency control for paper making stock



E. A. POlRlER RATUS FOR VOLUME AND CONSISTENCY Aug. 2, 1955 METHOD ANDAPPA CONTROL FOR PAPER MAKING STOCK 5 Sheets-Sheet 1 Filed Dec. 28, 1950Evm fl.Po iaiieH,

E. A. POIRIER Aug. 2, 1955 2,714,341 METHOD AND APPARATUS FOR VOLUME ANDCONSISTENCY CONTROL FOR PAPER MAKING STOCK Filed D80. 28, 1950 3Sheets-Sheet 2 'I ll 0 4, A w 9 H 6 A HU Hl l H I M 7 V II 0 i I x 6 m MHHIIIH l IIHHJMW. u 6 m a 4 E 4. w. a 9 9 J ,A w :I a 4 6 III. F 8

Aug- 2, 1955 E A POIRIER 2,714,341

METHOD AND APPARATUS FOR VOLUME AND CONSISTENCY CONTROL FOR PAPER MAKINGSTOCK Filed Dec. 28, 1950 3 Sheets-Sheet 5 IOE 1230882303 E'Hm a2. Pqimy, 31 %w 724% flifoafieeg United States Patent OflFice 2,714,341Patented Aug. 2, 1955 METHOD AND APPARATUS FOR VOLUME AND CONSISTENCYCONTROL FOR PAPER MAKING STOCK Ernest A. Poirier, Waterville, MaineApplication December 28, 1950, Serial No. 203,122 Claims. (Cl. 92-46) Inearlier patents I have disclosed various methods and apparatus fortreating a stream of paper-making stock to minimize the variations inits consistency, as Well as the resultant variations in the weight ofsolid material which is delivered to a supply point. The presentinvention is especially concerned with the solution of the problems towhich prior methods and apparatus of this general character have beendirected and it aims to improve such methods and apparatus with a viewto simplifying both. More specifically, the invention aims to devise animproved method of controlling the volume of stock discharged from thestream, which method can be further adapted to provide a means ofsimultaneously controlling both consistency and volume. It is also animportant object of the invention to provide an improved gate mechanismfor regulating the flow of astrearn of paper making stock and to combinethe gate mechanisms with other stock regulating equipment.

These and other objects and novel features will be more fully understoodand appreciated from the following description of a preferred embodimentof the invention selected for purposes of illustration and shown in theaccompanying drawings, in which Fig. 1 is a vertical, sectional view ofan apparatus embodying features of this invention;

Fig. 2 is a plan view of the apparatus shown in Fig. 1;

Fig. 3 is a vertical, sectional view taken on the line 33 of Fig. 1,illustrating a gate mechanism;

Fig. 4 is a vertical, sectional view taken on the line 4-4 of Fig. 1;

Fig. 5 is a fragmentary enlarged plan view of the discharge side of theapparatus shown at the right-hand side of Fig. 1;

Fig. 6 is a plan, cross-sectional view taken on the line 6-6 of Fig. 4;

Fig. 7 is a detailed cross-sectional view of a portion of the controlvalve mechanism;

Fig. 8 is an elevational view of a modified form of regulator in whichthe discharge gate mechanism of the invention is employed for thepurpose of controlling volume in another way; and

Fig. 9 is a plan view of the structure shown in Fig. 8.

Referring first to Figs. 1 and 2, the construction there shown comprisesan elongated tank or casing 2 near the left-hand end of the casing. Thespace in it is partly divided by an adjustable wier structure 3 and by astationary dam 4 into the tank and overflow compartments 5 and 6,respectively. A supply pipe 7 conducts stock into the former While anoverflow pipe 8 carries away the surplus. The wier includes an uppersection 3 adjustable by means of the hand wheel 10 and a lower section 3which may be raised and lowered by means of a handle 11. The formercontrols the normal level or head maintained in the supply or intakecompartment 5, while the latter is opened only to flush out thesesections of the casing.

The compartment 5 forms one section of a conduit which conducts thestock through the entire casing, other elements being two restrictedpassages 12 and 12' which lead the stock into a control chamber 13 fromwhich it may be discharged through the adjustable delivery gategenerally indicated by the letter G. The two passages 12 and 12' areconveniently formed by means of two partitions 14 and 14' which aresecured to the upper side of the casing and extend downwardly below thedam 4 at either side thereof, as shown in Fig. 1.

Diluting water, which may consist either of clear or white water, withcertain ingredients added if desired, is supplied to the stream atseveral points therealong from the pipe 15 shown at the upper right-handside of Fig. 1. As shown in Figs. 1 and 2, the supply of diluting wateris led through the supply pipe 15 which is connected into one side of acontrol valve, indicated by the letter C. This valve governs thedelivery of diluting water in the stream in the tank 2 and includes aspecial tubular fitting 16 having an upwardly turned end. As illustratedin Fig. 7, the upper end of the fitting 16 is rounded and made smooth tocooperate with a flexible circular diaphragm 17, the margins of whichare clamped between the lower face of an annular rim 18 integral withthe dome 19 of the valve casing and a similar annular portion 20 of thelower body section of the valve.

Control of the flow of fluid material through this valve may be achievedhydraulically or pneumatically, either liquid or air being conductedinto the chamber 21 above the diaphragm 17 by means of a pipe 22. Thisfluid is under pressure and the degree of such pressure utilized iscontrolled by a pilot valve 23 slidable in the valve casing 24 mountedon top of the dome 19. The tapered end of this valve 23 cooperates witha correspondingly tapered seat 25 to control the escape of fluid fromthe dome 27 and into the exhaust or discharge pipe 26. Preferably wateris used for this purpose, a very small quantity being required.Consequently, the discharged water is delivered into the casing 2 at thepoint indicated in Fig. 1.

In accordance with the invention the operating movement of the valveplunger 23 may be produced by a float 28, Fig. 1, which is supported inthe stream of paper making stock in the control chamber 13. The stem ofthis float may, for example, be connected through parallel motion levers30 and rod 32 with a yoke 34 adjustably secured to valve 33, as shown inFig. 7. The upper of the levers 30 is fulcrumed at 36, Fig. 1.

Consequently, as the diluting water is led through the pipe 15 from asource under suflicient pressure to make it overflow the upper end ofthe fitting 16, the float 28 will be raised, if the level of the stockin the control chamber 13 is sufficiently high, thus seating the valve23 and preventing the escape of fluid from the dome 19. Pressure thenbuilds up in the dome to the full value in the pipe 22, which should bemade suflicient to hold the diaphragm 17 seated firmly on the upper endof the fitting 16 at this time. It thus prevents the flow of additionalwater into the casing 2. When, however, the level of the stream in thechamber 13 drops, the float also will drop, thus cracking the valve 23open slightly and allowing some escape of fluid from the dome 19. Thisreduces the pressure on the diaphragm 17 and when that pressure isovercome by the pressure in the supply pipe 15 the diaphragm will belifted sufliciently to permit a controlled flow of diluting waterthrough the pipes P, P, P", and P.

It will be seen that by retarding the flow of stock from the controlchamber 13 by means of a discharge port of limited size, and by causinga resistance to the flow of stock as it enters the control chamber 13,there will result a series of different hydrostatic levels to whichsucceeding portions of the stream will rise. In Fig. 1 several differentlevels of this character have been indicated by dot and dash lines, asshown in compartment 5.; in restricted passageway 12; and in chamber 13,the direction of flow being indicated by the arrows.

It will also be apparent that the hydraulic head of stock in the inletcompartment and the size of the discharge port means may be so adjustedthat the level of the stock in the control chamber 13 and, consequently,the hydrostatic pressure which forces the stock through the dischargeport, will vary inversely with changes in consistency of successiveportions of the stock flowing through the apparatus. This, of course, isdue to the fact that as consistency increases, i. e., as the stockbecomes heavier, the resistance to its flow through the restrictedpassages 12 and 12 will also be increased and the level of stock incontrol chamber 13 will drop, thus producing less hydrostatic pressureto force stock through the discharge port means. On the other hand, ifthe consistency decreases, i. e., becomes lightened, the fiow assumesmore nearly the nature of water. The resistance in the restrictedpassages decreases and the level of stock in the control chamber 13rises, thus producing greater hydrostatic pressure to force stockthrough the discharge port means.

Since there is to be expected a more or less constant change inconsistency of the stock entering into the pipe 7, the weight of solidsactually delivered through the discharge port means varies materiallyand obviously may depart from delivery of a desired constant weight ofmaterial which should go into the formed web or sheet of paper. It ishighly desirable for this reason to provide an automatic weightregulation of stock. Some regulation is, as' noted above, automaticallyachieved by increase or decrease in hydrostatic pressure in the chamber13 resulting from change in the hydrostatic level which varies thepressure forcing material out, but it is found that the change in volumeof stock forced through the discharge port in this way is not sufficientto produce a correct weight regulation.

While it is possible to use hand operated adjusting mechanism fordischarge ports to change the volume of stock delivered at any giventime, it will readily be appreciated that to attempt to make suchchanges by hand from one time to another as consistency changes developin the flowing stock, would scarcely be feasible or practical from aneconomic standpoint.

In order to overcome this difliculty, therefore, I have devised aspecial method and structure for discharging stock so as to produce anautomatic'weight regulation based upon changes in hydrostatic level ofthe stock. The gate structure is best shown at the right-hand side ofFig. 1 and also in Figs. 3 and 4. As there illustrated the casing 2 isprovided with a pair of converging side wall portions 40 and 42 to whichis secured a gate frame made up of upper channeled sections 44 and 46.Solidly mounted in the channel sides at the front thereof, as viewed inFig. 4, are two transverse plate members 48 and 50, one of which isbetter shown in cross-section in Fig. 6. As noted in the latter figure,the inner surfaces of the plates 48 and 50 are formed with respectivediagonally extending slots 52 and 54, in which are transversely disposedkeys 56 and 58.

Mounted for sliding movement against the plates 48 and 50 are two outerpanel sections 60 and 62 which are formed with two diagonal slotscoinciding with the slots 52 and 54 and adapted to slidably engage withthe keys 56 and 58, as suggested in Fig. 6. An inner panel 64, bettershown in Fig. 6, is also mounted in the frame for vertical slidablemovement relative to the panel sections 60 and 62, and being held andguided in the channel members by means of bars 66 and 68 which lieclosely adjacent to opposite inner edges of the channel sections, assuggested in Fig. 6.

The outer panel sections 60 and 62 are normally located in aspaced-apart position, such as that shown in Fig. 4, and at their upperends are provided with a pair of pivoted links 70 and 72 carried in athreaded block 74 in threaded engagement with a screw member 76 whichextends through a top frame plate 78, as illustrated in Fig. 4.

The screw member 76 may be rotated by a handle 80. Fixed on the upperend of the screw member 76 at a point above the top frame plate 78 is agear 82 in mesh with a second gear 84 carried by a second screw member86. The latter member is rotatably received through an extension of thetop frame plate and has its lower end threaded into a bracket 88 whichis, in turn, bolted to the inner panel section 64.

With the aid of the double screw arrangement it will be evident that byrotating the handle in one direc tion or the other, the outer panelsections 60 and 62 may be raised and lowered, and simultaneously areguided toward and away from one another by the keys 56 and 58 acting inthe slotted portions of the panels. Also, at the same time, the innerpanel section 64 will be moved by the screw 76 in an opposite verticaldirection to the direction of vertical movement of the panel sections 60and 62.

In the fully opened position of the several panel sections illustratedin Fig. 4, these members provide a bottom discharge port 90, a seconddischarge port 92 located above the first port, and an overflow port 94located at still a higher level and extending above the hydrostaticlevel of stock in the control chamber 13. When .ne outer panel sections60 and 62 are raised by means of the handle 80, they move toward oneanother, decreasing the width of the overflow port 94 and thus limitingthe volume of overflow from the hydrostatic head in control chamber 13.Simultaneously the inner panel section 64 is moved downwardly todecrease the height of the discharge ports 90 and 92.

The eifect of this dual movement is to both reduce the size of ports 90and 92 and also to maintain a substantially square shape in the areasincluded by the discharge ports 90 and 92. This square shape betterallows the stock to flow through the relatively decreased dischargeareas without the likelihood of material stagnating or clogging, asmight be the case if the areas were comprised by much higher butnarrower shaped discharge ports. It is pointed out that at the overflowopening 94 movement of gates toward and away from one another changesthe size of the opening 94 in widti only, its height remaining the same.

As noted above, the opening 94 extends well above thelevel of fluidmaterial indicated in dot and dash lines in control chamber 13. It willthus be apparent that if stock is flowing through the discharge ports 90and 92 and a change of consistency takes place, resulting in an increasein the hydrostatic head of the fluid in the chamber 13, it is possibleto produce an overflow of material between the outer panel sections 60and 62 in an amount which varies with the spacing between these members.

Consequently, by regulating their spacing for a desired consistency itis readily possible to provide for automatic delivery of a varyingvolume of stock which supplements the volume discharged from ports 90and 92 to deliver a total amount of solids normally required. There isthus produced an automatic weight regulator which will deliver asubstantially constant weight of solid material as the level of thestock in the chamber 13 rises and falls as a result of changes inconsistency in the material being delivered into that chamber.

In thus carrying out weight regulation it should be understood that thedischarge outlets 90 and 92 deliver varying amounts of material inaccordance with the hydrostatic pressure which is exerted on the liquidflowing through these ports. However, this varying pressure is notsuflicient to furnish delivery of the required amount of solid material,and the spacing of the overflow opening 94 is so chosen as to cooperatewith these two discharge ports and furnish an additional volume ofgallonage which, at a point of proper adjustment, will give a correctWeight of solids regardless of the changes which may take place in theconsistency of the stock.

In conjunction with the above described automatic weight regulation,there may also be carried out simultaneous regulation of the consistencyof the stock so that both operations are effected without interferenceof one with the other as the required changes take place. Consistencyregulation by means of the above noted apparatus will now be described.

As stock enters the inlet pipe 7 it overflows the adjustable dam 3 incompartment 5 with a part of the stock flowing upwardly in therestricted area between the partitions 14 and 4, and then downwardlybetween the members 14 and 4, with the restricted areas causing thestock to assume a hydrostatic level in compartment 12 which is somewhatlower than the hydrostatic level in compartment 5. Since there is acontinuous flow of stock into the chamber 13 and out through thedischarge ports described, there will be formed another hydrostaticlevel in chamber 13 slightly lower than the level in the restricted area12. It will be obvious that if the discharge ports were closed thelevels in all three compartments would equalize.

Assuming that the stock is at a relatively heavy consistency, dilutionwater is introduced through the pipes P, P, P" and P from the supplypipe 15 and the valve C. These pipes operate to furnish dilution waterat four points at once, including the overflow compartment 6, the inletcompartment 5, the restricted compartment 12, and the control chamber13.

When stock enters the inlet 7 at a lighter consistency, the frictionalaction, namely wall friction and internal friction, of each fibertwisting its way through the restricted chambers 12 and 12' becomes lessand less and increases the velocity flowing through said restrictedarea, and the level or hydrostatic head in chamber 13 rises and causes adisplacement of the float 28. The latter member rises and shuts off thesupply of dilution water through its arrangement of pilots connected tothe hydraulic valve. This immediately retards the dilution water and thestock becomes heavier in consistency. The velocity then decreases, goingthrough the restricted passage, and the float adjusts itself with thelevel in chamber 13 to maintain proper dilution for the requiredconsistency.

It is pointed out that the consistency regulator may be adjusted to anydesired point of consistency by raising or lowering the float throughits adjusting stem and wheel 28a shown in Fig. 1. An important featureof the consistency regulator of the invention is the multiple distribution of diluting water for any given consistency setting of thefloat. The distribution points are so arranged that the several pointsof delivery cooperate with one another and operate to quickly controlconsistency deviation at specific localized areas where dilution can bemost efliciently realized.

The dilution at P is important under almost all conditions of operationand especially so in keeping the stock in the stock chest at aconsistency nearest to the point of efiiciency of whatever stock pump isbeing used. It is found that a centrifugal pump delivers a gallonagewhich depends upon consistency and has a high point of eificiency at onedefinite consistency value. Therefore, by more continuously maintainingthe consistency at that definite optimum consistency value, a moreefiicient operation may be realized. Certain other difiiculties inconnection with pumping, resulting from changes in consistency, maysimilarly be corrected by introducing dilution water from pipe P intothe overflow. It will be seen that introducing dilution Water from pipeP creates a more uniform head in compartment 6 and aids either acentrifugal pump or a plunger type pump to handlevarying consistencies.

The. dilution at P, with the arrangement illustrated in Fig. 1, occursimmediately above the inlet pipe 7 and 6 is preferably formed with aT-shaped outlet which is so positioned as to prevent stock from forcingitself into the dilution pipe P, and yet permits a better and moreeflicient mixing action at the point of entry of the stock into thecasing.

Dilution pipe P" is of similar T-shaped outlet construction and islocated in the restricted passageway 12 and, here again, provides for amore eflicient mixing action taking place concurrently with mixing atother points, so that a more wide spread correction is quickly carriedout throughout the region of restriction. Dilution from pipe P'" isformed with a T-shaped outlet and is so located as to deliver dilutionwater directly into the control compartment 13 so that a source ofcorrection from dilution water is available precisely at the point wheredemand for more or less dilution water originates. In this position pipeP' may deliver dilution water to any low point desired or a pointequivalent to the usual or normal consistency.

It should be observed that in the multiple dilution water supplyarrangement described, the: consistency control is very closely relatedto the weight regulation control. Since weight regulation is dependentupon the overflow through the port 94, and since the consistency controlis also responsive to changes in the same hydrostatic level, operationof one modifies operation of the other, and of course the change actsinstantaneously on both controlling agencies.

It should also be noted that the amount of stock flowing from theseveral discharge gates to some extent controls the stock overflowingthe surplus overflow gate 3, therefore making possible a wide variationin production without need for readjusting the height of the overflowgate.

It is intended that the overflow gate mechanism with its adjustablepanel sections may be combined with other types of consistencyregulators such, for example, as those employing modified forms ofrestrictors, examples of which have been described and claimed in myearlier patents.

I may also desire to practice the method of the invention and to utilizethe gate mechanism with a conduit for conducting a stream of stock inwhich consistency changes are present in the absence of a specialrestr'ictor device, but where a changing hydrostatic level may beproduced. Thus, in Figs. 8 and 9 I have shown a stock chest from whichstock is discharged to a centrifugal pump 102 and then pumped into theconduit 104 to provide a hydrostatic level which has been indicated indot and dash lines.

An overflow gate 106 similar to the improved overflow gate of theinvention already described is provided at an upper side of conduit 104and is so arranged that stock from the hydrostatic level will overflowinto an outlet member 108. A surplus overflow port 110 returns surplusmaterial to the chest 100.

In this form of the invention the hydrostatic level of stock will riseand fall in the conduit 104 in accordance with changes in consistency ofstock pumped upwardly by the centrifugal pump 102. It should berecognized that a centrifugal pump has a maximum efliciency point atwhich it will provide a substantially constant delivery at one givenconsistency value. Since the action of the centrifugal pump is todeliver a relatively greater volume of stock at a low consistency thanit does at a high consistency, it will be apparent that the level ofstock 12 rises upwardly on light consistency and drops down on heavyconsistency in substantially the same manner of variation which has beendescribed with reference to the apparatus shown in Figs. 1 to 7,inclusive. Consequently, by properly setting the adjustable panels ofthe gate 106 in the manner already described, it becomes possible todeliver a varying volume so limited as to produce a net amount of solidsin operation. It is pointed out that this is an extremely efiicient andsimplified form of gate application which, for some types ofinstallation, is highly desirable and economical.

From the foregoing it Will be evident that this invention provides amethod of weight regulation as well as weight and volume regulationinvolving the steps of producinga changing hydrostatic level andproducing an overflow in response to changes in hydrostatic level andlimiting the overflow in a predetermined manner. These operations may becarried out either separately or in conjunction with the step ofcreating a high degree of internal friction in a confined portion of astream of stock, and the speed of response of the consistency control isdirectly related to the same hydrostatic level which is utilized todeliver an overflow for a required volume correction. The method thusdescribed, by reason of its unusually wide range of control, necessarilycan be adapted to fluid materials in volving mixtures of solids in aliquid vehicle other than those solids commonly employed in the papermaking industry. For example, the method may be practiced in connectionwith mixing solids such as chemical bodies, either in finely divided orfibrous form, orin other conditions of subdivision.

The invention also involves a highly novel gate mecha nism, as well as acombination of novel gate mechanism with a multiple diluting watersystem, and a specific form of restrictor device combined therewith. Thescope of the invention, therefore, is to be understood as being limitedonly by the extent of the claims appended hereto.

What is claimed is:

1. A volume and consistency regulator for paper making material,comprising a casing having a stock inlet compartment and a controloutlet compartment through which a stream of paper making material ispassed, wier means located between the inlet compartment and the outletcompartment for restricting portions of the stream and producing adifferential in hydrostatic head in the two chambers, said hydrostatichead in the control compartment varying inversely with changes inconsistency of the paper making material, means for supplying dilutionwater to the stream of paper making material, float means operating inresponse to changes in hydrostatic head to regulate feeding of dilutionwater from the supply means, adjustable gate means communicating withthe control compartment and adapted to provide for discharge of papermaking material therefrom, said gate means including inner and outerpanel members movable toward and away from one another to define aplurality of discharge ports located one above another, one of saidports occurring at an upper side of the control compartment in aposition to define an overflow outlet, and means including screwadjustment members for varying the position of the panels and therebylimiting the overflow in accordance with changes in hydrostatic level insaid outlet compartment so as to maintain delivery of a substantiallyconstant weight of solid material during changes in consistency in thestream.

2. A consistency regulator for paper making stock comprising a conduitfor a stream of stock, said conduit being formed with a dischargeoutlet, means for supplying stock 1 to said conduit under apredetermined head, resistance means in said conduit for creating africtional resistance to the flow of said stream and so impeding saidflow that a hydrostatic head will be created in another part of saidstream, which head will vary with changes in the consistency of thestock, means for holding a supply of diluting water under a constanthead, means for furnishing the diluting water to the stream inaccordance with a demand which varies inversely with changes inconsistency of the stock, and outlet means including adjustable panelsections movable into a position to define both an outlet port and anoverflow port for discharging stock in amounts which vary inversely withthe consistency of the stock and which are so limited as to producedelivery of a substantially constant weight of solid material.

.3. A consistency and volume regulator for paper making stock comprisinga casing, said casing being separated into a series of connectedcompartments in which a stream of paper making stock may be caused toassume successively lower hydrostatic heads varying in accordance withconsistency changes of the stock, means for supplying dilution water tothe stock in accordance with changes in consistency of the stock anddischarge gate means communicating with one of said compartments, saiddischarge gate means comprising a frame having a pair of outer movablegate panels received at one side thereof, and a third inner panel memberslidably supported at an opposite side'of said frame therein, saidpanels being formed with openings for discharge of paper making stocktherethrough, two of said panels being movable toward and away from oneanother to define an overflow passageway normally extending above thelevel of paper making material in said compartment.

4. A consistency and volume regulator for paper making stock comprisinga casing having an inlet compartment adapted to receive and hold thepaper making stock at a desired hydrostatic head, wier means supportedin the casing to form a control compartment and a restrictor compartmentcommunicating with both the control compartment and the inletcompartment, outlet means for discharging paper making material from thecontrol compartment, said outlet means including an adjustable. gatemechanism having a plurality of discharge openings therein, one aboveanother, and means for varying the size and shape of the openings, saidgate mechanism comprising a frame, a plate vertically slidable in theframe, said plate having an opening formed therethrough, a pair of outercooperating panels and an inner panel movable in the frame in directionsvertically and horizontally of the casing to open and close the openingsin the said plate, said cooperating panels at their upper sides definingan overflow passageway for discharge of stock from the controlcompartment, and screw means for simultaneously adjusting both the outerand inner panels to provide for releasing a constant weight of paperstock during changes in consistency of the stock.

5. A consistency and volume regulator for paper making stock, comprisinga casing having an inlet compartment adapted to receive and hold papermaking stock, wier means supported in the casing to form a controlcompartment and a restrictor compartment communi-. cating with the inletcompartment, outlet means for discharging paper making material from thecontrol compartment, said outlet means including an adjustable gatemechanism having a plurality of discharge openings formed therein, oneabove another, said gate mechanism comprising a frame, a closure sectionvertically slidable in the frame, said closure section being formed withopenings therethrough, a pair of cooperating panels located against thesaid closure section, means for moving the panels in directionsvertically and horizontally of the frame, said closure section beingadjustable simultaneously with the cooperating panels and in an oppositedirection thereto to vary discharge outlets formed by the panels, andsaid cooperating panels defining an overflow passageway for overflowstock from the control compartment.

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